Telephone apparatus



Dec. 11,1923. 1 1,476,953

W. L. DAVIS TELEPHONE APPARATUS lFiled Dec. 9, 1920- 2 Sheets-Sheet 1 Dec. 11 1923.

w. L. DAVIS- TELEPHONE APPARATUS 2 SheetS-Sheet 2 Filed Dec. 9, 1920 07 fi M Patented Dec.-11 ,-1923.

- unlrso STATES LJDAVIS, OF CHICAGO, ILLINOIS.

;' mnmarn'onn APPABATUS.

Application filed December 9, 1920. Serial 1o.-429,305.

To all whom it may concern:

Be 'it known that I, WALTER LnDAvls, a citizen of the United States, residing at Chicago, inthe county of Cook and State of Illinois, have invented certain new and useful Improvements in Telephone Apparatus, of which the following i'sa specification.

My invention relates to improvements in telephone apparatus and is of particular service in connection with apparatus used in intercommunicating or house telephone systems.

The principal objects of the invention are to provide an improved com blnation telephone receiver and-transmitter set having self-contained means for selecting difi'erent stations of those comprising the system; to provide an improved circuit for such a system; to provide improved switching means and apparatus suitable for use with such .a self-contained set; to provide an improved construction of selector switch; and, in general, to provide an improved system and apparatus of the character referred to.

In the drawings, which illustrate a preferred embodiment of my invention a use.

the handle 13 is an insulatmg block com- Fig. 1 is a front elevation of'the combined set;

Fig. 2 is a side elevation thereof;

Fig. 3 is a section taken on the line 3-3 of Fig. 2;

Fig. 4 is a section taken on the line 4-4 of Fig. 2; c

Fig. 5 is a section taken on the line 55 of Fig. 1; and Fig. 6 is a circuit diagram-0t a single station. Referring to the drawings, it will be seen that the station set comprises in general an ordinar to which the special apparatus of my invention is applied. Such combination set c mp-rises a microphone transmitter 10 with the usual mouthpiece 11, a watchcase receiver 12, and a handle 13 on which the said parts may be conveniently mounted for simultaneous Located within the tube or barrel of posed of two parts 14 and 15 suitably united together, for instance, by screws '16, the block as a whole being secured in the handle, tube in any convenient manner. On the block 14 there is mounted a groupof switch springs 17, 18, 19, 20, and 21, suitably insulated from each other. The switch spring 18 has secured on its outer end a block or hand microphone and transmitter tip 22 of fiber or other suitable insulating material, and'is engaged by the stem 23 of a button 24,'the reduced end of which protrudes through an aperture in an escutcheon plate 25 secured to the'outsicle of the handle 13.- Sai-dpush button 24 is normally forced outwardly by means of a coil compression spring 26 surrounding the stem 23 and-located in a small opening 27 in the block 15.

The springs 19 and 20 are permanently insulated from each other by means of a small spacer 28. Normally, the springs 17 and 18 are in contact with each other and thekother springs are not in engagement. When the push button 24 is depressed by the thumb,

the contactbetween the springs 17 and 18 is broken and the spring 18 engages and makes contact with the spring 19, also causing the springs 20 and 21 to contact with each other.

On the front of the handle there is mounted a bell-shaped shell 29 provided with a flange 30 to which, by means of screws 31, there is secured a support or mounting block 32 preferably constructed of bakelite or similar insulating material. Said block serves asa support for the selector mechanism, which may be removed from the instrument as a whole by releasing the screws 31. p

The said block 32 is provided with a central aperture and the back of the block is recessed slightly, as shown at 33, to form a seat for the selector block 34, which comprises a disk of bakelite or similar material. Said disk is centrally apertured and has one side thereof formed with a circular recess 85. Secured in said aperture in the selector block' 34 is a threaded sleeve 36 having a head 37 on the inside of the block. A look nut 38 threaded on the sleeve 36 serves to clamp said sleeve tightly in engagement with the block, the said sleeve constituting part of the means for securing the contact block in theset. The end of said threaded sleeve 36 extends through the aperture in the mounting plate or block 34 and accommodates a lock-nut 39, by means of which the selector block unit is clamped to the mounting plate 34.

The lock-nut 39 is formed with a radial extension arm 40, and has at its end a In 41 marked with a radial notch 42 to comb- 'tute a guide or pointer for determining the station to which the apparatus is connected.

Said pointer 42 cooperates with a numbered disk 43, the edge of which is knurled or milled in order to enable the user to rotate said disk into any desired position so as. to connect the set with any particular station of the system. 'Assuming that the particular station-herein illustrated is No. 1 of the system, it will be seen that the set is in normal position, that is to say, connected with its home line, which is No. 1.

I will now describe the means by which the selection of the station-is effected. It will be observed that on the back of the selector block there are exposed a plurality of contacts corresponding in number with the number of figures on the dial 43, said contacts taking the form of a series of concentrically-arranged equi-spaced plugs 44 forced into apertures drilled all the way through the said block 34. It will be noticed that the contact faces: of said plugs 44 are flush with the rear face of the.

selector block 34, there being a space 45 provided in its aperture, said space being in depth substantially half of the thickness of the block 34. Said space 45 is provided for the purpose of facilitating the connection of the line wires 46. ,To make such connection, there are drilled radially towards the center of the blocbk 34 a series of apertures 47 of sufficient size to admit the overall diameter of the insulated wire 46, the end 48 of said wire being bared to permit of its being soldered to the bottom of the contact plug 44. It will be observed that this construction is exceptionally economical tomanufacture and assemble, since the soldering of the 'wire to the contact plug may be effected through the aperture 45 prior to the assembly of the selector unit in the set, and such soldering does not in any way disturb or injure the insulation of the line wire or the contact plug 44.

The contact faces of the plugs 44, which are ground off flush with the face of the se lector block 34, cooperate with a brush or contact arm 49 which revolves as a unit with the dial 43. The connection between the brush and the dial is afforded by. an inner sleeve 50 journaled in the threaded fixed sleeve 36, the outer end of said sleeve 50 being swaged or forced into an aperture centrally drilled in the dial 43. The hub 51 of said contact arm or brush 49 is split, as shown at 52, and accommodates a clamping screw 53 threaded into the hub at that side of the slit remote from the screw-head so that the arm 49, through which the inner end of the sleeve 50 passes, may be clamped in any desired position of adjustment.

The actual contact between the brush arm 49 and the contact plugs 44 is effected by means of a small pin 54 located in an aperture 55 and normally forced outwardly of said aperture by a coil spring 56. Preferably, the contact button to which the home line is connected is marked with a center punch or the end of a small drill to furnish a slight recess or seat for the pin 54, in order to make it somewhat easier for the user to determine by the feel of the dial when his instrument is connected with the home line.

Ringing of another station is effected by a button 57 havin a stem 58 of brass or other suitable metal which extends throu h a plug 59 secured in the inner end of t e inner sleeve 50. Said button 57 is normally forced outwardly by means of a coil spring 60, the outward movement of said button 57 being limited by a pin 61 passing through the inner end of the stem 58.

On the blocks 14 and 15 there is secured a contact plate 62 which is so located with respect to the selector that when the button 57 is depressed, the inner extremity of the stem 58 will contact with said plate 62. In the circuit diagram, said contact stem 58 is represented by the arrow 63.

The wires which lead to the positive and negative poles of' the common battery 64 and to one pole of the bell 65, together with wires leading to all the other stations of the system, are all contained in a single cable 66 leading out of the bottom of the instrument.

In the operation of the system, the normal condition of the instrument or set is such that when the dial is moved into such position that the notch 42 is registered with the number on the dial corresponding with the number of the station, the station is in ringing connection with its home line and also adapted to be placed in a talking connection with its home line when the talking button 24 is depressed. This will be apparent from an inspection of the circuit diagram shown in Fig. 6. If a distant station desires to ring the station herein shown, the dial at said distant station is turned to No. 1, which will connect the brush at said station with the line of the station herein shown. The button 57 at the distant station is then depressed, which connects line No. 1 with the negative pole of the common battery 64. Since one terminal of the bell (35 is permanently connected to the home line and the other terminal is normally connected to the positive pole of the battery through the contacts of the switch s )rings '17 and 18, the bell will be actuated. ressurc of the talking button 24 at each station then places each of said stations in talking connection with line No. 1, the receiver circuit being closed through the contacts of springs 20 and 21, while the transmitter circuit is closed through the contacts of springs 18 and 19.

It will be observed that the arrangement of the parts is such that the whole instrument and all of the operating parts can be manipulated with one hand. The position of the button 24 is such that it comes normally under the thumb when the set is heldin the left hand in the usual talking position. It will be observed that the location ,of the dial 43 is such that it can be conveniently rotated by the thumb of the same hand which holds the set, and after the dial has been turned to the proper station, the thumb may then be used for pressing the ringing button 57 and thus calling the station to which the dial position corresponds.

It will be understood that the described details of construction and operation are merely illustrative of a single application of my invention, the scope of which is to be determined b reference to the appended claims, said 0 aims being construed as broadly as possible consistent with the state of the art.

I claim as my invention:

1. In a station set for intercommunicating telephone systems, the combination with a transmitter, a receiver, a common handle on which said transmitter and said receiver are mounted for contemporaneous use, and a. selector also mounted on said handle and located substantially at the grip portion thereof for connecting the station with another station in the s stem.

2. In a station set or intercommunicating telephone systems, the combination with a transmitter, a watch case receiver, a common use, and a selector also mounted on said' handle for connecting the station with another station 'of the system, and provided with a dial facing in the same direction as the receiver and suitably located on the handle whereby it ma be actuated by the hand which supports t e set.

3. In a station set of the class described, the combination of a tubular handle, a watch-case receiver mounted at one end of said handle, a transmitter mounted on the other end of said handle, a switch mounted within said handle for controlling the talkin circuit, a button on said handle for actuating said switch, and a selector for connectin the station with another, mounted on said handle adjacent said button, whereby said button and said selector may be actuated b the same hand which holds the set.

4. n a station set of the class described, the combination of a tubular handle, a watch-case receiver mounted at one end of said handle, a transmitter mounted on the other end of said handle, a switch mounted within said handle for controlling the talking circuit, a button on said handle for atcuating said switch, aselector for connecting the station with another, mounted. on sald handle intermediate its ends and adjacent said button, and contact means associated with said selector for ringing the station selected.

5. A selector, comprising in combination a block of insulatin material, a series of contact buttons fixed y mounted in said block and exposed on one side of said block, a brush movable over said exposed faces, and wires connectedrto said buttons, said block having an opening in the edge thereof to admit each wire, and an aperture in the back thereof to permit soldering of the end of said wire to the under side of the button.

6. A selector comprising in combination a block of insulating material, a series of integral contact buttons fixedly mounted in said block and exposed on one side of said block, said buttons extending only part wa through the thickness of said block, sai block being provided at its ed e with o nings respectively leading to the rear aces of said contact buttons and having apertures in the -back thereof to expose the rear faces of said buttons, and line wires respectively located in said openings and soldered to the rear faces of said buttons.

7. In combination, a supporting plate, a

disk on one side of said support and a pointer on the otherside of said support, both permanentl secured to said support, said support an disk bein centrall apertured, a concentric series 0 contact uttons mounted on said disk, a sleeve journaled in said aperture, a dial on one end of said sleeve cooperating with said pointer, a brush on the other end of said sleeve cooperating with said contacts, a contact plate, and depressible means contained within said sleeve for at will making contact with said plate.

8. A selector, comprising in combination a supporting plate provided with a central aperture, a disk on the back of said plate provided with a series of rearwardly-facing contact buttons, lines connected to said buttons, a headed sleeve extending through said disk and plate, means on said sleeve for preventing rotation of the sleeve in said disk, a lock-nut on the outer end of said. sleeve for clamping together the previouslymentioned parts, a ointer on the front of said plate and space from the center there- 'of, a dial cooperating with said pointer, a

sleeve on which said dial is-carried, extending loosely through said first sleeve, a brush on said inner sleeve cooperating with said contacts, .and a ush button slidably mounted within said inner sleeve.

9. In a hand telephone, the combination with a transmitter, a receiver, a common handle on which said transmitter and said receiver are mounted for contemporaneous use, and a. station selecting dial also mounted on said handle and located substantially at the gri ortion thereof.

vdli TER L. DAVIS. 

